Pretreatment and Fractionation of Wheat Straw for Production of Fuel Ethanol and Value-added Co-products in a Biorefinery

An integrated process has been developed for a wheat straw biorefinery. In this process, wheat straw was pretreated by soaking in aqueous ammonia (SAA), which extensively removed lignin but preserved high percentages of the carbohydrate fractions for subsequent bioconversion. The pretreatment condit...

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Main Authors: Xiu Zhang, Nhuan P. Nghiem
Format: Article
Language:English
Published: AIMS Press 2014-08-01
Series:AIMS Bioengineering
Subjects:
Online Access:http://www.aimspress.com/Bioengineering/article/155/fulltext.html
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author Xiu Zhang
Nhuan P. Nghiem
author_facet Xiu Zhang
Nhuan P. Nghiem
author_sort Xiu Zhang
collection DOAJ
description An integrated process has been developed for a wheat straw biorefinery. In this process, wheat straw was pretreated by soaking in aqueous ammonia (SAA), which extensively removed lignin but preserved high percentages of the carbohydrate fractions for subsequent bioconversion. The pretreatment conditions included 15 wt% NH4OH, 1:10 solid:liquid ratio, 65 oC and 15 hours. Under these conditions, 48% of the original lignin was removed, whereas 98%, 83% and 78% of the original glucan, xylan, and arabinan, respectively, were preserved. The pretreated material was subsequently hydrolyzed with a commercial hemicellulase to produce a solution rich in xylose and low in glucose plus a cellulose-enriched solid residue. The xylose-rich solution then was used for production of value-added products. Xylitol and astaxanthin were selected to demonstrate the fermentability of the xylose-rich hydrolysate. <em>Candida mogii</em> and <em>Phaffia rhodozyma</em> were used for xylitol and astaxanthin fermentation, respectively. The cellulose-enriched residue obtained after the enzymatic hydrolysis of the pretreated straw was used for ethanol production in a fed-batch simultaneous saccharification and fermentation (SSF) process. In this process, a commercial cellulase was used for hydrolysis of the glucan in the residue and <em>Saccharomyces cerevisiae</em>, which is the most efficient commercial ethanol-producing organism, was used for ethanol production. Final ethanol concentration of 57 g/l was obtained at 27 wt% total solid loading.
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spelling doaj.art-053ca106943148abb1e068c44fa594522022-12-22T01:47:18ZengAIMS PressAIMS Bioengineering2375-14952014-08-0111405210.3934/bioeng.2014.1.4020140104Pretreatment and Fractionation of Wheat Straw for Production of Fuel Ethanol and Value-added Co-products in a BiorefineryXiu Zhang0Nhuan P. Nghiem1Department of Biological Sciences and Engineering, Beifang University of Nationalities, Yinchuan, ChinaEastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania, 19038 USAn integrated process has been developed for a wheat straw biorefinery. In this process, wheat straw was pretreated by soaking in aqueous ammonia (SAA), which extensively removed lignin but preserved high percentages of the carbohydrate fractions for subsequent bioconversion. The pretreatment conditions included 15 wt% NH4OH, 1:10 solid:liquid ratio, 65 oC and 15 hours. Under these conditions, 48% of the original lignin was removed, whereas 98%, 83% and 78% of the original glucan, xylan, and arabinan, respectively, were preserved. The pretreated material was subsequently hydrolyzed with a commercial hemicellulase to produce a solution rich in xylose and low in glucose plus a cellulose-enriched solid residue. The xylose-rich solution then was used for production of value-added products. Xylitol and astaxanthin were selected to demonstrate the fermentability of the xylose-rich hydrolysate. <em>Candida mogii</em> and <em>Phaffia rhodozyma</em> were used for xylitol and astaxanthin fermentation, respectively. The cellulose-enriched residue obtained after the enzymatic hydrolysis of the pretreated straw was used for ethanol production in a fed-batch simultaneous saccharification and fermentation (SSF) process. In this process, a commercial cellulase was used for hydrolysis of the glucan in the residue and <em>Saccharomyces cerevisiae</em>, which is the most efficient commercial ethanol-producing organism, was used for ethanol production. Final ethanol concentration of 57 g/l was obtained at 27 wt% total solid loading.http://www.aimspress.com/Bioengineering/article/155/fulltext.htmlWheat strawfuel ethanolvalue-added productsbiomassbiorefinery
spellingShingle Xiu Zhang
Nhuan P. Nghiem
Pretreatment and Fractionation of Wheat Straw for Production of Fuel Ethanol and Value-added Co-products in a Biorefinery
AIMS Bioengineering
Wheat straw
fuel ethanol
value-added products
biomass
biorefinery
title Pretreatment and Fractionation of Wheat Straw for Production of Fuel Ethanol and Value-added Co-products in a Biorefinery
title_full Pretreatment and Fractionation of Wheat Straw for Production of Fuel Ethanol and Value-added Co-products in a Biorefinery
title_fullStr Pretreatment and Fractionation of Wheat Straw for Production of Fuel Ethanol and Value-added Co-products in a Biorefinery
title_full_unstemmed Pretreatment and Fractionation of Wheat Straw for Production of Fuel Ethanol and Value-added Co-products in a Biorefinery
title_short Pretreatment and Fractionation of Wheat Straw for Production of Fuel Ethanol and Value-added Co-products in a Biorefinery
title_sort pretreatment and fractionation of wheat straw for production of fuel ethanol and value added co products in a biorefinery
topic Wheat straw
fuel ethanol
value-added products
biomass
biorefinery
url http://www.aimspress.com/Bioengineering/article/155/fulltext.html
work_keys_str_mv AT xiuzhang pretreatmentandfractionationofwheatstrawforproductionoffuelethanolandvalueaddedcoproductsinabiorefinery
AT nhuanpnghiem pretreatmentandfractionationofwheatstrawforproductionoffuelethanolandvalueaddedcoproductsinabiorefinery